scholarly journals Parametric profiler using a linearly frequency modulated signal.

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
V.I. Kaevitser ◽  
◽  
A.P. Krivtsov ◽  
I.V. Smolyaninov ◽  
A.V. Elbakidze ◽  
...  
Keyword(s):  
Experimental Model ◽  
Frequency Modulation ◽  
Wide Band ◽  
Linear Frequency Modulation ◽  
Frequency Range ◽  
Radio Engineering ◽  
Experimental Prototype ◽  
Chirp Signals ◽  
The Difference ◽  
Echo Sounder

At the Kotelnikov Institute of Radio Engineering and Electronics of RAS an experimental prototype of a parametric echo sounder-profiler with linear frequency modulation (LFM) of the sounding signal has been developed, manufactured and tested. Two chirp signals are emitted at frequencies of 144 kHz and 148 kHz. The difference reception frequencies have a frequency range of 1 kHz to 8 kHz. A wide band of differential frequencies is achieved by emitting two chirp signals. Laboratory and marine tests of the experimental model of the echo sounder-profiler have been carried out.

Target Detection

2018 ◽  
pp. 17-37
Keyword(s):  
Target Detection ◽  
Frequency Modulation ◽  
Linear Frequency Modulation ◽  
Transmitted Wave ◽  
Target Range ◽  
Differential Phase ◽  
Linear Frequency ◽  
The Difference

Target detection means to illuminate the target and then calculate its parameters, such a range, speed, azimuth, and altitude. The target range can be obtained using one of several methods: by calculating the time between the detected target echo and the transmitted wave, then calculating the difference in frequency between the received echo and the transmitted wave in the case of linear frequency modulation, and finally calculating the differential phase of the double detection of an echo obtained using two transmissions of different frequencies.

scholarly journals 3 cm Doppler scatterometer with full polarization sensing.

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
E.M. Zuikova ◽  
◽  
G.A. Baidakov ◽  
Y.A. Titchenko ◽  
M.B. Salin ◽  
...  
Keyword(s):  
Experimental Model ◽  
Frequency Modulation ◽  
Wind Wave ◽  
Experimental Results ◽  
Difference Frequency ◽  
Synchronous Detection ◽  
Wave Channel ◽  
X Band ◽  
The Cross ◽  
The Difference

The paper describes an experimental model of an X-band multi-polarization Doppler scatterometer developed at the IAP RAS with one antenna for receiving and transmitting, two generators with sinusoidal frequency modulation, slightly differing in frequency, and rigidly synchronized with each other. At the output of each of the two mixers, the co-polarizations are simultaneously distinguished in two quadratures at the beats and the cross-polarizations at the difference frequency. After filtering and synchronous detection, Doppler frequencies are obtained at all polarizations, which are then recorded on a computer for further processing. Experimental results obtained in the wind-wave channel of the large thermally stratified basin of the IAP RAS are presented.

Microwave wide band absorption by carbon from Corn cob-1

2016 ◽  
Vol 12 (2) ◽  
pp. 4204-4212 ◽  
Author(s):  
Maheshwar Sharon ◽  
Ritesh Vishwakarma ◽  
Abhijeet Rajendra Phatak ◽  
Golap Kalita ◽  
Nallin Sharma ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Agricultural Waste ◽  
Wide Band ◽  
Nickel Nitrate ◽  
Equivalent Amount ◽  
Frequency Range ◽  
Corn Cob ◽  
Different Temperatures ◽  
Band Absorption ◽  
5 Ghz

Corn cob, an agricultural waste, is paralyzed at different temperatures (700oC, 800oC and 900oC). Microwave absorption of carbon in the frequency range of 2 GHz to 8 GHz is reported. Carbon activated  with 5%  nickel nitrate showed more than 90% absorption of microwave in the frequency range from 6 GHz to 8 GHz, while carbon activated  with 10% Nickel nitrate treated corn cob showed 90% absorption  in the frequency range of 2.5 GHz to 5 GHz. Carbon showing the best absorption are characterized by XRD, Raman spectra and SEM . It is suggested that corn cob treatment   alone with KOH did not improve the microwave absorption, whereas treatment along with nickel nitrate improved the absorption property much better. It is proposed that treatment with nickel nitrate helps in creating suitable pores in carbon   which improved the absorption behavior because while treating carbon with 1N HCl helps to leach out nickel creating equivalent amount of pores in the carbon.

scholarly journals Band notched self complementaryultra wideband antenna for wireless applications

2018 ◽  
Vol 7 (2.8) ◽  
pp. 529 ◽  
Author(s):  
Ch Ramakrishna ◽  
G A.E.Satish Kumar ◽  
P Chandra Sekhar Reddy
Keyword(s):  
High Frequency ◽  
Return Loss ◽  
Wide Band ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Relative Dielectric Permittivity ◽  
Frequency Range ◽  
Ground Structure ◽  
Wireless Applications ◽  
Patch Edge

This paper presents a band notched WLAN self complementaryultra wide band antenna for wireless applications. The proposed antenna encounters a return loss (RL) less than -10dB for entire ultra wideband frequency range except band notched frequency. This paper proposes a hexagon shape patch, edge feeding, self complementary technique and defective ground structure. The antenna has an overall dimensionof 28.3mm × 40mm × 2mm, builton  substrate FR4 with a relative dielectric permittivity 4.4. And framework is simulated finite element method with help of high frequency structured simulator HFSSv17.2.the proposed antenna achieves a impedance bandwidth of 8.6GHz,  band rejected WLAN frequency range 5.6-6.5 GHz with  vswr is less than 2.

scholarly journals Co-designed radar-communication using linear frequency modulation waveform

2016 ◽  
Author(s):  
Michael J. Nowak ◽  
Zhiping Zhang ◽  
Yang Qu ◽  
Dimitri A. Dessources ◽  
Michael Wicks ◽  
...  
Keyword(s):  
Frequency Modulation ◽  
Linear Frequency Modulation ◽  
Linear Frequency
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